Method and means of perforating



May 16, 1939.

Re. 2.1,Qg5

AF. EA ONEILL METHOD AND MEANS OF PERFORA'I-ING CASINGS 2 Sheets-Sheet l xiigs ZEZZg/v Original Filed Feb. l2, 1935 May- 16, 1939. F. E. O'NEILI. R 21,085

METHOD AND MEANS 0F PRFORATIN'G CASNGS Original Filed Feb` 12, 1935 2 Sheets-Sheet 2 :lm y

* wf/vm? Reissued -May 16, 1939 UNITED STATES PATENT OFFICE METHOD AND S OF PERFORATING CASINGS Frank E. ONeill, Los Angeles, Calif., assignor to Edith L. ONeill, Glendale, Calif.

Original No. 2,634,768, dated March 24, 1936, Se-

rial No. 6,184, February 12, 1935.

Application `for reissue March 24, 1938, Serial No. 197,972

11 Claims.

the producing stratum of the earth formationv penetrated by the casing. Various methods and mechanisms have been provided for this purpose, including mechanical perforators which expand from the inside of the ycasing and form holes through the casing wall. These devices are for the most part diil'lcult to operate and do not extend their penetrating action further than the wall of the casing. It will be evident that better production of a well can be obtained if `;he earth formation around the perforations is also opened up to produce a more copious ow of fluid and it is the principal object of the present 1n- 90 vention to provide a perforating apparatus which will not only perforate the casing but will desirably penetrate the formation.

It is common practice at the present time to maintain the well full of drilling iluid during certain stages of the production of the well, and due to the weight and the character of the drilling fluid there will thus be within the well a column of drilling lluid which will produce an enormous hydrostatic head and will create at the bottom ,o of the well an appreciable hydraulic pressure.

In normal well operations this hydraulic pressure will be of the order of .one-half pound of pressure per square inch to the running foot of well bore. Heretofore when mechanical perforating devices have been used it has been necessary to manipulate them from the top of the well. It is another object of the present invention to provide perforating means, either actuated by the available hydraulic pressure provided with suit? able fluid pumping means or directly utilizing the pressure fluid to perforate the well casing vand to penetrate the formation therearound.

The present invention contemplates the provision of a perforating structure adapted to be lowered into a well in conjunction with the packer by which the fluid column of the well may be shut off from the perforating zone, and after which operation manipulation of the device from the top of the hole will release the pressure of the "0 iiuid column into the zone of perforation to create a perforating action due to said pressure.

'I'he invention is illustrated by way of example in the accompanying drawings in which:

Figure i is a view in longitudinal section showing the control unit to which the perforating unit is attached and by which it is manipulated.

Fig. 2 is a View in longitudinal section and elevation showing the perforating unit with which the present invention is concerned. 5

Fig. 3 is an enlarged View in central vertical section through the preferred form of perforating unit.

j Fig, 4 is a view in transverse section through the-perforating unit as seen on the line #-4 of Fig. 2 disclosing the lfluid passageway through the packer.

Fig. 5 is a view iii-transverse section as seen on the line 5=5 of Fig. 2 disclosing the perforating nozzles and theirrelation to the iluid passageway.

Referring more particularly to the drawings, l0 indicates a well casing to be perforated by the device with which the present invention is concerned. Il indicates -a drill pipe adapted to be u projected downwardly into the Well casing and to carry the perforating structure. This structure comprises two units, the controlyunit shown in Fig. 1 of the drawings and the perforating unit shown in Fig. 2 of the drawings. The control unit comprises an upper collar I2 threaded at its upper end to receive the drill pipe I I and threaded at its lower end to receive the cylindrical housingl of a trip valve I4. This valve is formed with a downwardly projecting member I5 at its lower end carried by a cylindrical body I6. This body may reciprocate vertically within a retainer sleeve Il mounted in the upper end of the housing I3. Radial openings I8 are formed through the wall of the portion I6 and within these openings balls I9 are mounted for radial movement. Disposed within the cylindrical portion I6 of the valve is a plunger 20 which may reciprocate vertically and which is formed with an annular recess 2| adapted at a certain position of move- 40 ment of the plunger to move downwardly into alignment with the balls I9 and to permit the balls to have inward radial movement. The plunger is provided with an enlarged head 22 at its upper end to be struck by a weighted object 4.- dropped downwardly through the drill pipe. 'I'he plunger 2li, the cylindrical'extension -IB of the valve, and the retainer sleeve Il are so designed as to insure that when the plunger is in its uppermost position theballs I9 will be held outwardly to wedge against the lower face of the retainer sleeve I1 and to cause the balls to be thus locked in a position lto hold the valve structure I4v in its lowermost position. In this lowermost position the extension I5 of the valve rests upon a valve 55,

rectionQ Fluid ow ducts 21 are formed radially vthe mandrel 3| extends.

through the valve structure I4 and communicate with the central Abore 28 receiving the valve plunger 28. A central duct 29 is formed upwardly through the valve plunger to permit fluid to flow from the opening 24 through the valve and into the drill pipe Il when the valve ball 23 is released from its seat.

A spring collar 38 is secured at the lower end of the Vvalve housing I3 and is also attached to a tubular mandrel 3l which .extends downwardly therefrom. The lower end of the tubular mandrel 3| is internally threaded and receives the upper extension of a main valve 32. Slidably mounted -on the tubular mandrel adjacent its lower end is a. packing box 33 which receives packing 34 and also carries a packing nut 35. The packing nut 35 circumscribes the tubular mandrel 3| and extends into the lower end of the packing box 33 so that the packing 34 may be tightened. 'I'he packingv box 33 also carries a tubular valve seat 35 which cooperates with the main valve 32 to normally close the lower end of the mandrel 3|. An adjustable tension nut 31 is threaded on to the upper end ofthe packing box 33 and has an end wall through which Interposed between this end wall and the end face of the collar 38 isa helical expansion spring 38 which acts to force themember 38 and the member 31 apart so that the valve 32 will rest normally upon its valvey seat 36. A central passageway 39 is formed through the valve 32 and a plurality of radial fluid inlets 48 are formed through the wall of the valve 32 to communicate withI the central passageway 39. Thus when the valve 32 has moved to a lower position and is unseated with relation to the valve seat fluid may pass upwardly around the valve 32 and .into the mandrel 3| through the openings 39 and 4 8. Disposed beneath the valve 32 and carried thereby is a circulating valve sleeve 4| within which an expansion spring 42 occurs. This spring acts to hold a circulating valve ball 43 on its seat to close the passageway 39 against the upward flow of fluid thereinto, except at such times as excessive fluid pressure is created within the drill string and forces the ball valve downwardly from its seat. Mounted upon the lower' end of the packing box 33 and extending downwardly to enclose the main valve 32 and the circulating valve 43 is a cyhndrical valve housing 44, the lower end of which is closed save for a central threaded opening 45 into which an equalizing valve mandrel 46 is threaded. This mandrel extends downwardly into the central passageway of an equalizer valve body 41 and terminates in an enlarged head portion 48. A y 49 is interposed between the mandrel and the alve body 41 so that rotation oi' the mandrel and the valve body may be effected in unison. A packing nut 58 circumscribes the mandrel 46 and is adjustably mounted in the upper end of the valve body 41. The packing nut is formed with an annular recess 5| at its upper end having outlet ducts 52 in communication therewith. The equalizing mandrel 46 is formed with a plurality of-radial openings 53 which may be brought to register with the annular passageway 62 Then the mandrel is at the upper end of its stroke as limited by the head 4a'. Mounted at the lower en'd of the valve body 41 is a bottom sub 54, which has a lower threaded pin extending into the threaded opening of a valve collar 55 of the perforating unit shown in Fig. 2. The lower end of this valve collar is fitted with an enlarged valve member 56 having a tapered end face adapted to seat against a valve seat 51 under certain conditions, as will be hereinafter described. The valve collar is mounted on to the upper end of a tubular body member 58 which extends downwardly through a packing unit 5&1.V 'Ihis unit is here shown as comprising the upper valve seat 51, a. plurality of 'resilient packing rings 68, anda base member 6I. 'I'he base member is formed at its top with a counterbore 62 to receive a. sleeve 63 which is circumscribed by the packing ring and which is threaded into the valve' Y seat 51. I'he lower end of the sleeve is formed with a collar which limits its upward movement. A bore 64 extends downwardly from the counterbore and within the base 6I. This bore is of a materially larger diameter than the tubular body member 58 which extends through it. .Below the bore 64 a reduced borel 85 occurs which is of substantially the same diameter as that of the tubular body 58, and forms a sliding t therewith, A packing gland 66 is carried at the lower end of the base 6| and around the body' 58. Attached to the lower extension of the base 6I and threaded therewith is an lexpansion cone 61 around which a plurality of slips 68 are arranged.

These slips are `carriedupon reins 69 pivoted to a slip rein collar 18 mounted at the upper end of a tubular cage 1|. 'I'hebody 58 telescopes through the'tu'bular cage and carries a seating pin 12 which moves in a bayonet slot 13 to lock the cage 1| in position upon the body 58. The cage carries a plurality of bow-shaped anchor springs 14 whichv may engage the inner face of a casing within which the device is beingused. The body 58 extends downwardly through the cage and carries a coupling 15 at-its lower end which cpupling in turn receives a perforated nipple 16 through which fluid may pass upwardly into the body 58 in a manner to be hereinafter described.

At a point 1n the 1ength or the base el, within which the bore 64 occurs, a plurality of perforating nozzles 11 are mounted. These nozzles are disposed within threaded radial bores 18. Each nozzle comprises an outer threaded sleeve 19 mounted within the bore 18 and having a shoulder 88'at the inner end of the bore, and a nozzle tip 8| slidablerwithin member 19 and yieldably held in a retracted position by spring 8|', and

through which nozzle fluid may be projected from j the bore 64 outwardly against a surrounding casing as the nozzle is forced outwardly to form a perforation as indicated at 82 in Fig. 3 of the drawings. A iluid circulating valve 84 is mounted through the wall of the base 6| and controls communication of fluid into the b ore 64. The circulation valve structure 84 comprises a valve ball 85 adapted to rest against a removable valve seat the geological formation through which the cas- The structure here shown provides 11 against the surface to be abraded. It will be recognized that liquid may be forced downwardly and outwardly through the nozzles 11 by a force created by other means than the head of the accumulated column of impounded liquid, such for example as by the usual mud Dump present at the well, and by which additional pressure can be imposed upon the liquid being forced downwardly and outwardly from the nozzles.

In the operation of the present invention the control unit as shown in Fig. l and the perforating unit as shown in Fig. 2, are assembled with the control unit uppermost and this structure is then mounted at the lower end of the drill pipe II to be inserted into the well. When the control unit is ready for insertion care, must be taken to insure that the trip valve structure I4 shall be locked so that the valve ball 22 will be held firmly on its seat over the opening 24. In this position it will be recognized that the drill stem II will be sealed off from the fluid which will be penetrated as the tool is lowered into the hole. At the same time the` spring 38 holds the mandrel 3| and the circulating valve housing 34 in a position to maintain the main valve 32 on its seat 36. The perforating unit is held in its locked position by the engagement of the lock pin 12 with the hooked upper end portion of the slot 13, at which time the slips 68 will be held in their lowermost position and the valve seat 51 will be held in its lowermost position and out of engagement with the valve memberv 56. As the entire assembled structure is lowered into the well the uid present in the well may flow upwardly through the ,perforating nipples 16 into the body 58 of the perforating unit and then upwardly through the equalizing mandrel 46 and into the housing structure 44 where further upward ilow of the fluid will be stopped by the valve 32 which is held in a closed position upon the seat 36 by the spring 38. If accidental movement of thek member 44 occurs due to the fact that the perforating unit encounters an obstruction which prevents or retards its downward movement sufficiently to overcome the expansive action of the spring 38, or if the pressure of the fluids within the well should be sufficient to overcome the tension of the spring 38 the valve 32 might open and permit the iiuid to enter the tubular mandrel 3|. The further upward flow of fluid would, however, be prevented due to the fact that the valve ball 23 is locked on to its seat by the trip valve mechanism I4. Thus the upward limit of flow of fluid within the tool prior to the time the trip valve I4 is opened would be to this trip v alve. It will be recognized that as the device is lowered into the well throughthe fluid it is necessary for the fluid to be bypassed through the packer. This is accomplished by lthe pressure of the fluid which lifts the valve ball from its seat 86 and allows uid to pass upwardly into-the space 64rof the base 6I of the packer'. This fluid will then pass upwardly. through the member 63 and outwardly into the well casing I8' through the valve seat 51. Due

-to this arrangement there willv be no difilculty pin 12 carried on the body 58 from the hooked upper portion of the slot 13, thus permitting the body 58 to move downwardly while the cage 1I is frictionally held by engagement with the casing wall. As the body 58 moves downwardly the cone 61 will force the slips 68 outwardly to positively grip the wall and to prevent further downward movement of the structure whichincludes the cone 61, the base 6I and the packer 59. When the packer is thus moved to its limiting position the valve collar 55 and the valve 56 will move downwardly so that the valve 56 engages the valve seat 51 and exerts pressure to deform and distend the packing rings 63 and-to cause them to expand into the casing Il) and to seal off all of the fluid column above the packing from the area of the casing below the packing. After the valve 56 has been thus set it'will be evident that the valve 85 will be moved on toits seat to close the opening through thevalve seat 84 and to prevent downward flow of fluid from the passageway 64. When the packer has beenset as previously described a perforating operation may take place. This is brought about by the secondary action of the controlunit. The first operation of the control unit after the packer is seated is for the collar 3D and the mandrel 3I to move downwardly so 4that the valve 32 will be lowered from .its valve seat 36 and so that fluid may pass upwardly through the radial ducts .40 and into the central duct 39 of the valve ele- `ment 36. When this has been established a flow of iuid may'be subsequently permitted by dropping a weighted instrument, commonly called a go-devil, vdown through the drill pipe II until it strikes the head 22 of the plunger 20. At such a time the plunger will be moved downwardly to bring the annular recess 2| which is formed around its body into register with the balls I8, thus permitting them to move inwardly to a pointv of clearance and to allow the expansive action of spring 26 to move the valve element I6 upwardly so that the upward pressure of the fluid against valve 23 will lift it from its seat. The fluid from the well may then flow upwardly into the drill stem through the radial passageways 21 and the central passageway 28 of the member I6 and through the central passageway 29 of the plunger 20.

Prior to the time when the valves 32 and 23 of the control unit were opened there was a possibility that fluid from `the column of fluid above the packer 59 might have free flow downwardlyv within the casing, thence through the ducts 88 in the valve head 56, and then downwardly :i

through the packer 59 within sleeve member 63 and outwardly through the nozzle I1 into the casing. The fluid in the casing, both above and below the packing, will at this time be quiescent since the valves 32 and 23 are closed and prevent upwardly into the empty drill stem I I and as the fluid which is within the portion of the casing Ill below the packer is forced upwardly the fluid in the casing III above the packer will be forced downwardly under its weight and pressure. This fluid will pass through the ducts 88 in the valve 56, thence'through the sleeve 63 to the space 64 and then outwardly through the nozzle 11 under the pressure of the head of the column of fluid and at a high velocity. As the fluid forces .its way outwardly through the nozzle tip it will also force the nozzle tip outwardly into close proximity to the casing wall. 'I'his will ensure that the iiuid will be delivered directly to the surface tobe abraded. 'I'he fluid will act by abrasion to cut perforations through the casing and will also act to penetrate formation through which the casing extends. The spent fluid will then flow downwardly on the opposite side of the casing or Within it and find its way into the perforated nipple and thereafter will flow upwardly into the drill'stem.

It will be evident thatl the prime feature of invention is the abrasion of the wall of the casing at a desired depth within a well and by the action of the liquid which is ejected forcefully from the nozzles. It will be understood that if deemed desirable the positive pressure created by a pump mayl be imposed upon the liquid tol force it from the nozzles instead of utilizing the static pressure of a. column of liquid impounded within a well bore. In either of which events the liquid will be projected at high velocity against the wall of the well casing to perforate the same and to open up the formation therearound.

In the event it is desired to form other perforation operations the weight of the drill stem may be relieved from4 the perforating unit and the drill stem with the valve 32 may be drawn upwardly as the spring 38 expands so 4that the valve 32 will engage the seat 36. By this operation the upward uid flow into the drill stem may be interrupted, after which the structure may be further raised to relieve the pressure of the valve 56 from thevalve seat 5l so that the packer may be released anni moved to a different level than the casing'. When the packer is again set by imposingpressure onY the packer and expanding cone to force the slips into a setting position a further lowering of the drill stem will move the valve 32 from its seat and permit an upward surge of uid to again take place yinto the drill stem accompanied by a downward surge of fluid from the column above the packer and` outwardly through. the nozzles 11 to form another perforating operation. z This operation may be repeated so long as there is a sufficient difference in pressure between the column of fluid within the casing and the column of u'id within the drill stem. It will be evident, however, that eventually the two colt umns of fluid will equalize each other as to pres- For that reason the equalizing valve structure has been provided which will cause the ducts 5311i the equalizing mandrel 46 to move into register with the annular space 5I of the packing nut 5Il'and v will permit iluid to pass through thev opening 52 so that the pressure will be equalized through the tool as it is withdrawn.

'I'he invention as here disclosed has been concerned with the direct perforation of a well casing by the abrasiveV action of a high velocity stream of liquid caused to flow by the control of valve means associated with the device.

It will thus be seen that by the operation of the device here shown it is possible to perforate a casing by utilizing the pressure and abrasive actionof the column of uid present withinthe casing at the time the perforating operation is carried out, and to insure that this operation may be easily brought about by the simple manipulation of the drill stemfrom the top of the well.

While I` have shown ,the preferred form of my invention, as now known 'to me, it will beunderstood that various changes might be made in the combination, construction, and arrangement of parts, by those skilled in the art', without departing from the spirit of the invention as claimed.

Having thus described my invention, what -I claim and desire to secure by Letters Patent isz l. A method of perforating a welljcasing at the bottom of a well which consists in lowering'a device into the well and submerging `the same within the column of liquid present within the well, thereafter packing off the column of liquid within the well, and then establishing communication between a casing perforator responsive to fluid iiow and a compartment atreduced pressure whereby fluid from the column within the well,

may pass downwardly through the casing perforator responsive to iiuid flow and to cause actuation of the same;

2. A method of perforating a well casingwith- 'inrwhicn wen a column ofnuid stands, which method consists 4in introducing a -perforating nozzle into the well and submerging it Within the iiuid,` thereafter shutting oi the column of uid within the well to establish a uid head and then establishing communication between said iiuid column and an area 'of reduced pressure from a point below the perforating 'nozzle whereby a flow of fluid will be established from the column through the point of shut oil and the perforating vnozzle and then'ce into'a column under reduced into the well and submerging the same within the fluid, said conduit carrying a packer, a perforating 'nozzle and a valve adjacent its lower end, thereafter setting the packer to establish a delinite liquid head within the casing, then opening the valve to release the uid below the packer,

whereby the liquid in the column above the packer will flow downwardly and outwardly through the perforating nozzles to impingel against the casing wall and will then ilow upwardly through the valve and into the drill stem. 4. A device of the class described comprising a drill stem adapted to be lowered into a well con-v taining liquid, a packer carried by the drill stem adjacent its lower end, a nozzle carried by the -drill stem at a point below the packer and in having a passageway through the packer, a valve l adjacent the lower end of the drill.`V pipe and adapted to be operated from above ground, to establish and interrupt communication between the well and the pipe, and a. perforating devicezsl carried by the pipe at a point below the po'cker and being in constant communication with-the liquid in the well above the packer whereby when the valve is opened a `downward ow of liquid from above the packer and through the perfor-at# ing device may take place, after which said liquid may ilow upwardly through the open valve and into the drill stem.

' 6.Awel 1casingperforator comprisingadrill pipeadaptedtobeloweredintoawellcasingcontaining drillinguid, a packer carriedonthe drill pipe adjacent the lower end thereof, said pipe having a w eway through the packer,-a valve adjacent the lower end of the drill pipe and adapted to be operated from above ground, to establish and interrupt communication between the well and the pipe. a perforating device carried by the pipe at a point below the packer and being in constant communication with the liquid in the well above the packer whereby when the valvel is opened a downward ilow of liquid from above the packer-.and through the 'perforating device may take place, after which said liquid may iiow upwardly through the open valve and into the drill stem, and an equalizer' valve normally closed and adapted to open when the device is withdrawn from a well to' break the iiuid seal around the packer. l

'7. A casing periorating tool adapted to be inserted into a well which is illled with-drilling uid, which tool comprises a tubular member extending down into the well to a point below the area of the casing to be perforated, a packer through which said tubing extends, said packer including means to set the same at a desired position within the well a periorating nozzle carried below the packer and communicating with a fluid bypass through the packer and exterior-1y oi the tubularmember, valve means within the tubular member and adapted to be manipulated to establish and interrupt a ilow o! iiuid from the portion o1' the well below the packer upwardly into the tubular member, and a second valve disposed within the tubular member at a point above the rst named valve, said second valve being closed normally and being adapted'to be opened independently of the iirst named valve. Y

8. Acasingpertoraingtooladaptedtobeinsex-ted into avwellwhlch is lled with drilling iluid, which tool a tubular member'extendingdownmtothcwell toapointbelowthe area of the casing to be perforated, a packer through whichV said tubing extends, said packer including means to set the same at a desired position within the well, a pertorating nozzle carried below the packer and communicating with a uid bypass through the packer and exteriorly of the tubular member, valve means within the tubular member and adapted to be manipulated to establish and interrupt 'aow of fluid from the portion of .the well below the packer upwardly into the tubular member, a vsecond valve disposed within the tubular member at a point above the iirst named valve, said second valve Abeing closed normally and-beingbadapted to be opened independently of the iirst named valvel and an equalizer valve disposed in the tubular member and adapted to permit a ow of Huid through the portion of the tubular member which 'extends through the'packer when the deviceis being withdrawn from the well.

9. A method of periorating the casing of an oil well lled with drilling fluid which consists in lowering a iiuid flow responsive device into the well and submerging the same in the column of liquid standing in the well, thereafter packing ofi the column of liquid within the well, and then establishing communication between the column of liquid above the point of packing off and a compartment under condition of atmospheric pressure whereby the uid from the column above the point of packing o will pass through the ow device and will project a jet of said fluid against the casing wall to abrade and perforate the same.

10; A method of perforating a well casing, which consists in lowering a device into a. well, which device carries means whereby a jet of liquid may be projected to impinge against the wall 

